Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the annotations: discloses the approval-card preview of subject+message before sending, the email is sent as the requesting user (replies route to them), a hard limit of one reminder, and that completion arrives as a notification rather than a polled response. This is exactly the behavioral context annotations cannot convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core action, then packs voice, approval, limit, and completion into tight clauses with no filler. It is dense with several distinct concerns in one paragraph, but each sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, and the description compensates by explaining how the result surfaces (notification with draft-page counts, don't poll) plus the confirmation flow and send limits. An agent has everything needed to invoke and follow through correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the field descriptions already carry the load (baseline 3). The description adds authoring guidance beyond the schema — 'short, human, says why THEIR knowledge matters and that it takes ~15 minutes' — which shapes how `message` and `subject` should be written.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: 'Emails the guest link for an existing interview.' The word 'existing' distinguishes it from compass_interviews_create, and the framing detail (from the requesting user) further narrows its purpose. An agent can place it without opening any sibling schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Says to use it for existing interviews and gives clear operational rules — invite plus ONE reminder, the third ask is the user's conversation, and don't poll. It implies but never explicitly names the sibling alternatives (create vs invite vs revoke), so it stops short of full routing guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.